C-protein from rabbit soleus (red) muscle.
A new form of skeletal-muscle C-protein has been isolated from rabbit soleus (red) muscle. This new form of C-protein has been purified to homogeneity by a procedure similar to that used to purify C-protein from white skeletal muscle. In soleus muscle, only this new form of C-protein could be detected, whereas in psoas (white) muscle, only the previously identified form of C-protein was detected. The content of C-protein in rabbit soleus muscle is comparable with that found in psoas muscle. Other rabbit skeletal muscles composed of a mixture of fibre types contained at least two forms of C-protein. C-Protein derived from red skeletal muscle bound to myosin isolated from either red or white tissue, with maximum binding occurring at a ratio of approximately 13 microgram of red C-protein/100 microgram of myosin. Polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate indicated that C-protein isolated from red skeletal muscle has a molecular weight approx. 7% greater than that of C-protein isolated from white skeletal muscle. The amino acid content of both forms of C-protein was similar but major differences in the mol % of isoleucine and threonine were found. Antiserum against C-protein from white rabbit skeletal muscle formed a single precipitin line with rabbit C-protein on double in agar. This antiserum did not form a precipitin line when diffused against red C-protein from rabbit skeletal muscle. Also, this antiserum bound specifically to the A-band region of myofibrils isolated from psoas (white) muscle, but it did not bind to myofibrils prepared from soleus (red) muscle.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002352:Carrier Proteins; D002645:Chickens; D004591:Electrophoresis, Polyacrylamide Gel; D005455:Fluorescent Antibody Technique; D005779:Immunodiffusion; D009124:Muscle Proteins / Q000302:isolation & purification; D009132:Muscles / Q000032:analysis*; D009218:Myosins; D011485:Protein Binding; D011817:Rabbits; D000099163:Myosin Binding Protein C
D000596:Amino Acids; D002352:Carrier Proteins; D009124:Muscle Proteins; D009218:Myosins; D000099163:Myosin Binding Protein C